A self-driving vehicle (also referred to as an autonomous vehicle or a driverless car) is a vehicle that is capable of sensing its environment and navigating without much human input. An autonomous car may be used to offer on-demand transportation service, such as acting as an unmanned taxi. Autonomous driving technology may offer many benefits, such as reducing transportation cost, reducing the needs for parking space, reducing the number of vehicles need, reducing traffic congestion, and the like. However, there are still many challenges and risks associated with autonomous vehicles, such as safety, security, and privacy issues.